Various types of air spoilers are already known in the art and in this connection attention is directed to typical patents such as German Pat. No. 109,199 issued Mar. 26, 1928, U.S. Pat. No. 3,415,566 and U.S. Pat. No. 3,866,967. Also other types of air shields have been mounted on top of the truck cab and also on the front face of the trailer body. Wind shields have been of varying types such as the one shown in U.S. Pat. No. 3,866,967.